Whenever I turn on the PC there is sound coming from the fan as if it is loose or free, somewhat wobbly sound so I want to open the back and check myself
You will need to unscrew the bottom cover to take it off, and remember to unplug the battery before doing any repairs. The fans should be on top of the motherboard, and you can replace them with replacements from Walmart, Ebay, and maybe even Amazon or Aliexpress.